Research on a prediction method of wind environment for a region consisting coastal area and off-shore structures

本研究的目的是发展一种预测复杂地形下近海和近海地区风环境的数值和实验方法。在数值方法方面，我们重点发展了计算地形的网格生成方法、计算高雷诺数流的方法（如LES）以及计算入口和地面边界条件的技术。因此，我们成功地开发了一种网格生成方法，通过使用矩形网格近似技术，使我们能够轻松有效地生成计算网格。这种方法将非常有用，在一个新的功能，因为计算机的能力将逐年发展。采用LES方法模拟了高雷诺数流动。在湍流模型中，LES是一种最有希望模拟湍流场的方法。对于边界条件，为了在计算机域的入口给出一个合适的湍流条件，我们采用了预域方法来计算湍流流入。在风洞实验中，进行了复杂地形上气流的平均速度测量和流动可视化实验，并与数值分析结果进行了比较。除近地面区域外，两者结果基本一致。综上所述，虽然沿海地区风环境的数值和实验预报方法还存在一些问题，但我们已经成功地建立了一个由数值分析和风洞试验组成的系统。

The objectives of the present research are to develop a numerical and experimental method to predict the wind environment for a region consisting of off shore and near sea in a complicated terrain. For the numerical method, we have focused on the development of grid generation method for computing terrain a method for computing high Reynolds number flows, such as LES, and a technique for boundary conditions for the inlet and ground. As the results, we have successfully developed a method for grid generation, by using a rectangular grid approximation technique, which enable us to generate a computational grid easily and effectively. This method will be very useful in a new feature, because the computer ability will develop year by year. A LES method has been employed to simulate high Reynolds number flows. Among turbulence models, LES is a most hopeful method for the simulation turbulence field. For the boundary conditions, to give a suitable turbulent conditions at the entrance of the computer domain, we have adopted a pre-domain method to compute the turbulent inflows. For the wind tunnel experiment, mean-velocity measurement and flow visualization experiment of the flow over a complex terrain was carried out to compare the results with those in numerical analyses. Both results show almost good agreement except for the region near ground.To sum up, although there still remain a couple of problems both in numerical and experimental method for the prediction of wind environment near coastal area, a system consisting of the numerical analysis and wind tunnel experiment has been successfully developed.